1. Field of the Invention
The present invention relates to a storage control device and enclosure-unit power control method.
2. Description of the Related Art
A storage control device comprises a storage section in which a multiplicity of hard disk drives are connected as an array and which provides a host computer (‘host’ hereinbelow) such as a server with a logical storage area (logical volume). In order to improve reliability, the storage control device provides the host with a RAID (Redundant Array of Independent Disks)-based redundant storage area.
The volume of data managed by enterprises and so forth is increasing on a daily basis. Therefore, a storage control device that is capable of suitably increasing the stored content in accordance with an increase in the data volume is preferable. Therefore, a storage control device that is capable of providing a storage area suited to the desires of the user through the connection of a plurality of additional enclosures that provide a storage area to a base enclosure that governs the control function has been proposed (Japanese Application Laid Open No. 2001-339853).
According to the prior art that appears in Japanese Application Laid Open No. 2001-339853, the start or stop of the supply of power to the base enclosure and the start or stop of the supply of power to each of the additional enclosures are linked. As a result, in cases where the storage control device is completely stopped, the supply of power to each of the additional enclosures can be completely stopped automatically by stopping the supply of power to the base enclosure.
According to further prior art that appears in Japanese Application Laid Open No. 2000-293314, the respective magnetic disk devices constituting a RAID group are moved to power savings mode.
According to the prior art that appears in Japanese Application Laid Open No. 2001-339853, the power supply operation for the base enclosure and the power supply operation for the respective additional enclosures are linked and the result is poor from the perspective of reducing the power consumption amount of the storage control device.
In contrast, in the prior art that appears in Japanese Application Laid Open No. 2000-293314, the power consumption amount of the storage control device can be reduced in order to shift a magnetic disk device that has not been accessed for a fixed time to a power savings mode.
However, the prior art that appears in Japanese Application Laid Open No. 2000-293314 is lacking in terms of the curtailment of the power consumption amount of the respective magnetic disk devices constituting the RAID group and there is a further margin for improvement. That is, even in cases where the respective magnetic disk devices are shifted to power savings mode, power is still supplied to the control circuit section, cooling fan, and power source circuit in the enclosure, which continue to operate. Hence, there is a margin for improvement for the power consumption amount of the respective parts other than the magnetic disk device.